Actuating magnet of flat construction



Dec. 15, 1970 E. BAUSCH ACTUATING MAGNET OF FLAT CONSTRUCTION Filed Aug.12, 1968 Sheets-Sheet 1 III III IIIIL III IIIIIlIIlIlIl-m Fig.2

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Dec. 15, 1970 E. BAUSCH 3,548,353

ACTUATING MAGNET OF FLAT CONSTRUCTION Filed Aug. 12, 1968 3 Sheets-Sheet2 INVENTOR. Fig. 4

Dec. 15, 1970 BAUSCH 3,548,353

ACTUATING MAGNET OF FLAT CQNSTRUCTION Filed Aug. 12, 1968 3 Sheets-Sheet5 INVENTOR.

United States Patent 3,548,353 ACTUATING MAGNET OF FLAT CONSTRUCTIONEdmund Bausch, Kirchen-Hausen, Germany, assignor to Binder Magnete KG,Villingen, Black Forest, Germany, a corporation of Germany Filed Aug.12, 1968, Ser. No. 751,869 Claims priority, application Germany, Aug.11, 1967, 1,589,539 Int. Cl. H01f 7/08 US. Cl. 335-476 8 Claims ABSTRACTOF THE DISCLOSURE Actuating magnet of fiat construction, particularlyfor ofiice machines, data processing installations and the like,includes an E-shaped core having outer legs surrounded by a respectiveenergizing coil so that the respective ends of the outer legs arelocated within the respective coil, and a double-armed armaturerotatably mounted on the middle leg of the core so that one arm of thearmature is displaceable into the interior of one of the coils, and theother arm into the interior of the other coil.

SPECIFICATION My invention relates to an actuating magnet of fiatconstruction as may be used, for example, for oifice machines, dataprocessing installations and the like.

In addition to the general requirements of the office machine industryfor actuating magnets having small overall volume (fiat construction),large numbers of switching operations without requiring maintenance(long life), short switching times and low cost, there has recentlyarisen the requirement for obtaining, with the smallest possible magnetdimensions, relatively high peak forces at the commencement of the liftor stroke. These peak forces occur, for example, in both directions of ayes-no circuit.

This problem has heretofore been avoided by using a polarizedelectromagnct having a stroke starting position fixed by a permanentmagnet. Such magnets are sluggish in operation, are subject toconsiderable wear, and provide the required forces only when they have arelatively large overall volume.

It is accordingly an object of my invention to provide an actuaingmagnet of extremely small dimensions, having a magnet force-distancecharacteristic which is adaptable to various problems in the applicationthereof, for example to a characteristic having high initial peak forcesas required in office machines.

With the foregoing and other objects in view, I provide, according tothe invention, an E-shaped core, having outer legs that are eachsurrounded by a respective energizing coil so that the leg ends arelocated within the coil. On the middle leg of the core there isrotatably mounted a two-armed armature, one of the arms thereof beingdisplaceable into the interior of one coil and the other arm into theinterior of the other coil.

In an actuating magnet according to the invention, therefore, two activeair gaps are each located respec tively inside an energizing coil andare defined at least partly by the iron core which is formed oflaminations of iron plates. By varying the construction of iron platede- 3,548,353 Patented Dec. 15, 1970 fining these active air gaps, agreat variety of magnet force-distance characteristic curves may beproduced. The construction according to the invention also provides avery favorable iron circuit with very small inactive air gaps, and thearmature is provided with a very small mass. Due to the fact that thearmature is rotatably mounted, the magnet force can be taken directlyoff the armature without the interposition of further structuralelements. The magnet force is applicable in various possible directionsin the plane of movement of the armature. Purely rotational and purelylinear forces and also forces along general curves are capable of beingrepresented. More particularly, it is significant that the magnetforcedistance characteristic is independent of the magnitude of thestroke, i.e. the force-distance characteristic obtained both for strokeslarger in comparison with the angle of rotation of the armature as wellas for strokes smaller in comparison with that angle is the same as fora normal stroke, since the characteristic is dependent solely upon themagnet system and not upon the location at Which the force is taken fromthe armature. In addition, the full mechanical energy output of themagnet system is available in each direction of the force and for eachstroke. This signifies a particular advantage for short strokes, sinceeven with very short strokes, for example of only a few tenths of amillimeter in length, the full stroke work or energy output and everydesired character istic are available, for example also a falling ordecreas ing charactertistic. In the case of the heretofore known magnetstructures, shortening of the stroke results in a loss of stroke work orenergy output. Furthermore, in the heretofore known magnets, a fallingor decreasing characteristic can be obtained only with considerablylonger strokes. Moreover, with the magnet according to the invention,there is no limitation in the length of stroke, since the initialposition of one armature side is fixed by the end position of the otherarmature side.

The rotatably mounted armature permits the use of the actuating magnetof my invention as a rotary magnet, exactly the same as a linear strokemagnet. In accordance with further features of my invention, by means ofa spring or by external forces, one position or both end positions ofthe armature are set as the zero position, and there is afforded asimple subdivision of the stroke into two diametrical operating ranges.The magnet may thus be used as simple stroke or lift magnet, double andand reversing stroke magnet, hinged armature magnet or double orreversing rotary magnet. The magnet is preferably provided with asymmetrical construction, however, it may also be constructedasymmetrically with regard to the location of the coils, air gaps, coreplates, armature and zero position of the armature.

Other features which are considered as characteristic for the inventionare set forth inthe appended claims.

Although the invention is illustrated and described herein as embodiedin Actuating Magnet of Flat Construction, it is nevertheless notintended to be limited to the details shown, since various modificationsand structural changes may be made therein without departing from thespirit of the invention and within the scope and range of equivalents ofthe claims.

The construction and method of operation of the invention, however,together with additional objects and advantages thereof will be bestunderstood from the following description of a specific embodiment whenread in connection with the accompanying drawings, in which:

FIG. 1 is a plan view, partly broken away and partly in section, of anactuating magnet according to the invention;

FIG. 2 is a view of FIG. 1 taken along the section line IIII in thedirection of the arrows;

FIGS. 3a, 3b and 3c are fragmentary perspective views of differentembodiments of the core and cover plates at the air gap in the magnet ofFIG. 1;

FIG. 4 is a plot diagram of magnetic force-distance characteristiccurve, corresponding to the magnet having the modifications shown inFIGS. 3a, 3b and 30;

FIGS. 5a and 5b are diagrammatic views of part of the armature of themagnet shown in FIG. 1 showing a resetting spring therefor connected atdifferent locations thereto.

Referring now to the drawings and first, particularly to FIGS. 1 and 2,there is shown an actuating magnet according to the invention having amovable armature 1, an E-shaped core 3, which may consist of a singleplate, as shown in FIG. 2, or of a number of plates, U-shaped coverplates 4 and 5 mounted laterally on the core 3, and energizing coils 2aand 2b, surrounding the outer legs of the core 3. The armature 1 isrotatably mounted in a bush 6 means of a pin 7 extending between twoT-shaped plates 9 and 10 that are secured to the middle leg of theE-shaped core 3-. One arm 1a of the armature 1 extends into the interiorof the coil 2a, and the other arm 1b of the armature extends into theinterior of the other coil 2b. When one of the two energizing coils 2aand 2b is energized, the armature 1 rotates about its bearing pin 7 andthe respective end arm of the armature 1 then plunges into therespective coil and abuts against an end face, provided with an adhesionsurface 11, of a respective outer leg of the E-shaped core 3.

FIGS. 3a, 3b and 30 show different construction of the core and coverplates of the outer legs of the E-shaped core, the cover plates formingcooperating members for the armature end arms. Depending on theparticular configuration shown in FIGS. 3a, 3b or 30 of the core andcover plates in the actuating magnet of my invention, a magneticforce-distance characteristic curve a, c or b is obtained, as shown inFIG. 4. These magnetic force-distance characteristic curves remainconstant, independently of the particular stroke of the magnet.

The actuating force may be determined or taken off directly from thearmature 1. Several possible ways of doing this are apparent fromFIG. 1. Thus, the magnitude and direction of the actuating force may betaken off directly as a linear force, as in the case of a liftingmagnet, by means of a diagrammatically illustrated rod 12. Anotherpossible way is to take oif the actuating force as a purely rotationalforce by way of the shaft or pin 7 bearing the armature l. A thirdpossible way for the direct takeoff of force is to provide the armature1, either on one or on both sides thereof with a cam surface 13 as shownin broken lines, which cooperates with a roller 14 so that, depending onthe shape of this cam surface 13, force can be taken off along apredetermined curve path.

FIGS. 5a and 5b illustrate two practical application of my invention, inwhich, by means of a tension spring 8, the armature 1 is fixed in zeroposition either at two initial positions as in the embodiment of FIG.5a, or at a middle position as in the embodiment of FIG. 5b, when thecoils are de-energized. A very great variety of force-distancecharacteristic curves may be produced thereby.

Since the active air gaps of the magnet are always located within thecoils 2a or 2b, the yoke faces of the core 3 are extremely wellprotected from dirt, since any dust particles or other contaminatingparticles, such as iron particles or the like, can at best only reachthe surfaces of the yoke or magnet core 3 through the narrow gap locatedbetween the armature arms In and 1b and the inner edge of the respectivecoils 2a and 2b.

The effective air gap is preferably located in the region of the upperthird to the upper half of each coil, as shown in FIGS. 1 and 2.

The armature 1, preferably constructed symmetrically with respect to itsaxis of rotation extending along the pin 7, is very insensitive tolinear vibrations. The bearing 6, concentrated into a relatively smallfriction surface, ensures a long operating life.

All the parts conducting magnetic flux may be produced, for example, bya stamping operation and can be assembled by welding, adhesion orriveting. A very economical manufacture is thereby assured. Theactuating magnet according to the invention may be operated by directcurrent or alternating current. In the latter case, the laminationplates of the core 3 and/or of the armature 1 should not be too thickand, for example, should be electrically insulated from one another byany suitable means.

I claim:

1. Actuating magnet of flat construction comprising an E-shapedelectromagnetic core, having a pair of outer legs and a center legtherebetween, each of said outer legs being flat and having a free end,a cover plate respectively covering the opposite fiat sides of saidouter legs and projecting beyond said free end of said outer legs, anenergizing coil having a hollow center surrounding each of saidplate-covered outer legs of said core, respectively, so that the freeend of said outer legs is disposed within the hollow center of therespective coil, and a double-armed armature rotatably mounted on saidcenter leg of said core so that one of the double arms thereof isdisplaceable into the hollow center of one of said coils and the otherof the double arms into the hollow center of the other of said coils andboth arms respectively receivable between the projecting cover plates ofeach of said outer legs and engageable with an end face at the free endof said outer legs, respectively.

2. Actuating magnet according to claim 1, wherein the respectivepositions of said cover plates project beyond said free ends of saidouter legs have given configuration for producing a predetermined magnetforcedistance characteristic curve.

3. Actuating magnet according to claim 1, wherein said core and saidcover plates are formed of stampedout metal plates, said metal platesbeing secured to one another.

4. Actuating magnet according to claim '1 wherein said core and saidarmature are formed of stamped-out laminations of magneticflux-conducting metal plates, the laminations of said core and of saidarmature, respectively, being welded to one another.

5. Actuating magnet according to claim 1 wherein said core and saidarmature are formed of stamped-out laminations of magneticflux-conducting metal plates, and layers of adhensive material betweensaid laminations for bonding together the laminations of said core andof said armature, respectively.

6. Actuating magnet according to claim 1 wherein said core and saidarmature are formed of stamped-out laminations of magneticflux-conducting metal plates, and rivet means for riveting together thelaminations of said core and of said armature respectively.

7. Actuating magnet according to claim 1 wherein said armature issubstantially centrally pivoted and including spring means anchored atone end to a point stationary relative to the pivot of said armature andextending transversely to said double arms of said armature over saidpivot thereof and secured to said armature at a location thereof beyondsaid pivot in a direction from said stationary point.

8. Actuating magnet according to claim 1 wherein said armature issubstantially centrally pivoted, and including spring means anchored atone end to a point sta- 5 tionary relative to the pivot of said armatureand extending transversely to said double arms of said armature towardsaid pivot thereof and secured to said armature at a location thereofbetween said stationary point and said pivot.

References Cited UNITED STATES PATENTS 1,315,777 9/1919 King 335-181X 61,532,045 3/1925 Davis 335 -181X 1,538,950 5/1925 Price 335-4812,679,563 5/1954 Katsumata 335268X BERNARD A. GILHEANY, Primary ExaminerR. N. ENVALL, JR., Assistant Examiner US. Cl. X.R. 335281

